Well stimulation tool and method for inserting a backpressure plug through a mandrel of the tool

Abstract

A well stimulation tool includes a well stimulation tool mandrel with an axial bore having an internal diameter large enough to permit a backpressure plug to be run through the mandrel into a tubing mandrel, such as a tubing hanger or a casing mandrel, to which the well stimulation tool mandrel is secured. This permits well stimulation to be performed through a tubing string suspended in the well by the tubing mandrel, without requiring wireline services.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This is the first application filed for the present invention.MICROFICHE APPENDIX[0002]Not Applicable.TECHNICAL FIELD[0003]The invention relates to the stimulation of oil and gas wells to improve production and, in particular, to a well stimulation tool used to deliver high-pressure fluids through a production tubing string of a well in order to acidize and / or fracture subterranean formations with which the well communicates.BACKGROUND OF THE INVENTION[0004]It is well known that many oil and gas wells require stimulation in order to increase production either as part of well completion, or as part of well work-over. Well stimulation involves the pumping of proppants and fluids under high pressure into the annulus of the well in order to break up subterranean formations and release hydrocarbons into the wellbore, where they can be extracted to the surface. Since it is generally not economically feasible to manufacture wellhead equipment th...

AI Technical Summary

Benefits of technology

[0015]The invention further provides a method of removing a well stimulation tool from a tubing hanger of a live well. The method includes the steps of inserting a tubing string of the well by inserting a backpressure plug tool through a well stimulation tool mandrel of the well stimulation tool, and sealing a central passage through the tubing mandrel using a backpressure plug to prevent an escape of well fluids to atmosphere when the well stimulation tool is removed.

Problems solved by technology

Since it is generally not economically feasible to manufacture wellhead equipment that can withstand extreme pressures, the wellhead must be isolated or removed during well stimulation in order to prevent potential damage and / or injury.

This permits the well to be stimulated without removing the production tubing from the well, which saves considerable time and reduces service fees.

First, the well may be “killed” by pumping an overbearing fluid into the well.

Killing the well is, however, generally not desirable for a number of reasons.

First, the operation is generally expensive and second, the production zones may be plugged or damaged by the overbearing fluid.

As is well understood by those skilled in the art, wireline services are expensive and time consuming.

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